Well, now I'll have to get some photos of mine and post them up. After reading what VPersh wrote I went home and looked at mine: he's 100% correct. There is no doubt a difference in the opening where the guard meets the bumper from one side of the guard to the other.
This dimension is also noticeably different. It looks to be about 5/16" larger from one side to the other. While mine is damaged from doing it's job guarding the bumper, I don't see any sign that it has been modified in any way. I do know for certain that it fits the drivers side much better than passenger, and I really don't think any of the damage done to it has anything to do with it's fitment. Kind of interesting.